Bollettino valanghe

Bitterroot

West Central Montana Avalanche Center
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Pericolo valanghe

Sun
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

Today, natural and human-triggered wet loose avalanches will become possible on sun-affected slopes. Look for indicators that the snow is losing strength, like rollerballs and natural point releases. If you find wet and unsupportable snow, stay out of avalanche terrain or move to cooler, shaded slopes. If you decide to step out to steeper terrain today, remember to use safe travel practices like riding one at a time. 

Problemi valanghivi

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Human triggered and natural wet loose avalanches will become possible in the afternoon on sun affected slopes.

    Yesterday, observers reported small natural and human triggered wet loose avalanches on steep, sunny slopes in the strong sunshine. Today, temperatures will be warmer, rising into the 40s, and the sun will shine again in the morning. However, increasing southwest winds and cloud cover in the afternoon will likely limit some warming, especially along wind-exposed ridgelines. 

    After a couple of sunny days, most solar-affected areas have some form of surface melt freeze crust. Today, that crust must break down before the snow can lose strength and lead to wet loose avalanches. If you find yourself in an area with strong sun holding fresh, dry surface snow, expect the snow to become wet quicker.

    The typical progression of wet loose avalanches involves rollerballs, and small point releases, leading to larger wet loose avalanches. If you encounter rollerballs or small wet loose avalanches, expect larger ones to follow. Remember that even small avalanches can have serious consequences in consequential terrain. 

    If you find yourself in wet, unsupportable snow or see natural, wet loose avalanches, it is time to step back out of avalanche terrain and be aware of what terrain is above you. You can also move to cooler, shaded slopes to find drier snow.

    (3/8/2024)

    A skier triggered small wet loose avalanche on an upper elevation south aspect on Sanders Peak in the Rattlesnake. Although it was small, it was easily large enough to knock you off your feet. 

    Photo: Arden Feldman

Avalanche Discussion

Today will be another great day to get out in the mountains, with warm weather and some sunshine in the morning. Wet loose avalanches on sunny slopes are the primary concern today. The avalanche danger is closer to Low this morning but will rise to Moderate by the afternoon as slopes heat up in the sunshine. 

We have dropped the wind slab and persistent slab problems today. Triggering a slab avalanche has become very unlikely, and they no longer reach the threshold to be included as full avalanche problems. However, this does not mean they are no longer a concern. Isolated and stubborn wind slabs may still linger in the highest terrain. Additionally, the poor snowpack structure that we have talked about for months did not suddenly disappear. The poor structure remains on some upper elevation slopes, especially those facing north and east. However, the buried weak layers have gained significant strength over the last few weeks and have been tested by several strong storms with minimal resulting avalanches. 

With a large enough trigger, like a cornice failure, it may still be possible to trigger a large slab avalanche. In the last week, we have observed a couple of large avalanches fail in that way. Stay heads up around large, overhanging cornices and steep, rocky, or noticeably shallow slopes. 

If you encounter any signs of instability, like cracking or collapsing, step back to lower-angle terrain. Additionally, if you dig down into the snow and find a poor snowpack structure with softer, faceted snow around hard crusts or loose, sugary faceted snow below a firmer slab, recognize the continued potential for a large and dangerous persistent slab avalanche. You can reduce your exposure by sticking to slopes free of terrain traps and without rollovers or convexities. Couloirs, chutes, long avalanche paths, cliffs, and exposed rocks or trees increase your risk. If you decide to step out into steeper terrain, be sure to use safe travel practices, such as riding one at a time and regrouping in safe zones. 

Please let us know what you see out there this weekend by submitting an observation. 

Ski and ride safe! 

Regioni coperte